#!/system/bin/sh
# fstab.sh
# Reads an fstab-style config and performs mounts/swapon without touching /etc/fstab.
#
# Usage:
#   ./fstab.sh [--su-options '<opts>'] [--log-file <path>] path/to/fstab.conf
# Examples:
#   ./fstab.sh --su-options '--mount-master --test' /path/to/fstab.conf
#   LOG_FILE=/sdcard/fstab.log ./fstab.sh /path/to/fstab.conf

set -u

# ---- defaults ---------------------------------------------------------------
su_options="--mount-master" # kann per --su-options überschrieben werden
: "${LOG_FILE:=}"           # optional via Environment

# ---- helpers ---------------------------------------------------------------
usage() {
  cat >&2 <<EOF
Usage: $0 [--su-options '<opts>'] [--log-file <path>] path/to/fstab.conf

Options:
  --su-options  String with options for su (default: '--mount-master')
  --log-file    Path to log file

Example:
  $0 --su-options '--mount-master --test' /path/to/fstab.conf
EOF
}

# ---- parse args ------------------------------------------------------------
args="$*"
while [ "$#" -gt 0 ]; do
  case "$1" in
  --su-options)
    [ "$#" -ge 2 ] || {
      echo "ERROR: --su-options needs exactly 1 argument." >&2
      usage
      exit 2
    }
    su_options="$2"
    shift 2
    ;;
  --log-file)
    [ "$#" -ge 2 ] || {
      echo "ERROR: --log-file needs exactly 1 argument." >&2
      usage
      exit 2
    }
    LOG_FILE="$2"
    shift 2
    ;;
  --help | -h)
    usage
    exit 0
    ;;
  --)
    shift
    break
    ;;
  -*)
    echo "Unknown option: $1" >&2
    usage
    exit 2
    ;;
  *)
    break
    ;;
  esac
done

FSTAB_FILE="${1:-}"

if [ -z "$FSTAB_FILE" ]; then
  usage
  exit 2
fi

if [ ! -r "$FSTAB_FILE" ]; then
  echo "File '$FSTAB_FILE' not readable." >>"${LOG_FILE:-/dev/null}" 2>&1
  echo "File '$FSTAB_FILE' not readable." >&2
  exit 2
fi

# Ensure 'su' exists
if ! command -v su >/dev/null 2>&1; then
  echo "ERROR: 'su' not found. Cannot perform privileged operations." >>"${LOG_FILE:-/dev/null}" 2>&1
  echo "ERROR: 'su' not found. Cannot perform privileged operations." >&2
  exit 2
fi

error_count=0
line_no=0

# --- logging helpers (both console and file) ---
log() { if [ -n "${LOG_FILE:-}" ]; then echo "$*" | tee -a "$LOG_FILE"; else echo "$*"; fi; }
warn() { if [ -n "${LOG_FILE:-}" ]; then echo "WARN: $*" | tee -a "$LOG_FILE"; else echo "WARN: $*"; fi; }
err() {
  if [ -n "${LOG_FILE:-}" ]; then echo "ERROR: $*" | tee -a "$LOG_FILE"; else echo "ERROR: $*"; fi
  error_count=$(expr $error_count + 1)
}

# --- safe single-quoting for building a command string for su -c ---
shell_quote() {
  # Output a single-quoted representation of $1, handling internal single quotes
  # 'abc'd' -> 'abc'"'"'d'
  printf "'%s'" "$(printf "%s" "$1" | sed "s/'/'\"'\"'/g")"
}

# --- run a command as root via su $su_options -c "..." preserving args safely ---
# Usage: run_root CMD ARG1 ARG2 ...
run_root() {
  cmd="$1"
  shift
  # Build a single string: CMD 'ARG1' 'ARG2' ...
  cmdline=$(shell_quote "$cmd")
  for a in "$@"; do
    cmdline="$cmdline $(shell_quote "$a")"
  done
  log "RUN (as root): $cmd $*"
  # Execute
  # shellcheck disable=SC2086
  su $su_options -c "$cmdline"
  rc=$?
  [ $rc -ne 0 ] && err "Command failed (exit $rc): $cmd $*"
  return $rc
}

# --- check if a mountpoint is already mounted (no root needed) ---
is_mounted() {
  mp="$1"

  if [ -r /proc/mounts ]; then
    grep -qs " $mp " /proc/mounts
    return $?
  fi

  return 1
}

# --- check if swap device is already active (no root needed) ---
is_swap_active() {
  spec="$1"
  base="$(basename "$spec")"

  if [ -r /proc/swaps ]; then
    awk 'NR>1{print $1}' /proc/swaps | grep -Fxq "$spec" && return 0
    awk 'NR>1{n=$1; sub(".*/","",n); print n}' /proc/swaps | grep -Fxq "$base" && return 0
  fi

  return 1
}

log "$0 $args"

# --- process each fstab line ---
while IFS= read -r rawline || [ -n "$rawline" ]; do
  line_no=$(expr $line_no + 1)
  line=$(echo "$rawline" | sed 's/^[[:space:]]*//;s/[[:space:]]*$//')

  case "$line" in
  "" | \#*) continue ;;
  esac

  # spec file vfstype mntops dump pass   (default 0 for last two if missing)
  set -- $(echo "$line" | awk '{print $1, $2, $3, $4, ($5? $5:0), ($6? $6:0)}')
  fs_spec=$1
  fs_file=$2
  fs_vfstype=$3
  fs_mntops=$4
  fs_freq=$5
  fs_pass=$6

  if [ -z "$fs_spec" ] || [ -z "$fs_file" ] || [ -z "$fs_vfstype" ]; then
    warn "Line $line_no: Invalid entry, skipped."
    continue
  fi

  echo "$fs_mntops" | grep -qw noauto && {
    log "Line $line_no: 'noauto' found, skipping $fs_spec -> $fs_file."
    continue
  }

  # --- swap handling ---
  if [ "$fs_vfstype" = "swap" ]; then
    if is_swap_active "$fs_spec"; then
      log "Line $line_no: Swap '$fs_spec' already active — skipped."
      continue
    fi
    if command -v swapon >/dev/null 2>&1; then
      log "Line $line_no: Activating swap: $fs_spec"
      if [ "$fs_mntops" = "sw" ]; then
        run_root swapon "$fs_spec" || true
      elif [ "$fs_mntops" = "-" ]; then
        log "Mount option '-' on swap, skipping."
      else
        run_root swapon -o "$fs_mntops" "$fs_spec" || true
      fi
    else
      err "Line $line_no: swapon not available."
    fi
    continue
  fi

  # --- bindfs filesystem mounts ---
  if [ "$fs_vfstype" = "bindfs" ]; then
    if is_mounted "$fs_file"; then
      log "Line $line_no: $fs_file already mounted — skipped."
      continue
    fi
    if ! command -v bindfs >/dev/null 2>&1; then
      err "Line $line_no: bindfs not available but requested (vfstype=bindfs)."
      continue
    fi
    if [ ! -e "$fs_file" ]; then
      log "Line $line_no: Creating mountpoint $fs_file"
      run_root mkdir -p "$fs_file" || {
        err "Line $line_no: mkdir failed for $fs_file"
        continue
      }
    fi
    if [ "$fs_mntops" = "-" ]; then
      log "Line $line_no: bindfs mount: $fs_spec -> $fs_file"
      run_root bindfs "$fs_spec" "$fs_file" || true
    else
      # bindfs versteht FUSE-Optionen via -o "<opts>"
      log "Line $line_no: bindfs mount: $fs_spec -> $fs_file (opts=$fs_mntops)"
      run_root bindfs -o "$fs_mntops" "$fs_spec" "$fs_file" || true
    fi
    continue
  fi

  # --- bind / rbind mounts ---
  echo "$fs_mntops" | grep -q bind && {
    if is_mounted("$fs_file"); then
      log "Line $line_no: $fs_file already mounted — skipped."
      continue
    fi
    if [ ! -e "$fs_file" ]; then
      log "Line $line_no: Creating mountpoint $fs_file"
      run_root mkdir -p "$fs_file" || {
        err "Line $line_no: mkdir failed for $fs_file"
        continue
      }
    fi
    if echo "$fs_mntops" | grep -qw rbind; then
      log "Line $line_no: rbind mount: $fs_spec -> $fs_file"
      run_root mount --rbind "$fs_spec" "$fs_file" || true
    else
      log "Line $line_no: bind mount: $fs_spec -> $fs_file"
      run_root mount --bind "$fs_spec" "$fs_file" || true
    fi
    continue
  }

  # --- regular filesystem mounts ---
  if is_mounted "$fs_file"; then
    log "Line $line_no: $fs_file already mounted — skipped."
    continue
  fi

  if [ ! -e "$fs_file" ]; then
    log "Line $line_no: Creating mountpoint $fs_file"
    run_root mkdir -p "$fs_file" || {
      err "Line $line_no: mkdir failed"
      continue
    }
  fi

  if [ "$fs_mntops" = "-" ]; then
    log "Line $line_no: Mounting $fs_spec -> $fs_file (type=$fs_vfstype)"
    run_root mount -t "$fs_vfstype" "$fs_spec" "$fs_file" || true
  else
    log "Line $line_no: Mounting $fs_spec -> $fs_file (type=$fs_vfstype, opts=$fs_mntops)"
    run_root mount -t "$fs_vfstype" -o "$fs_mntops" "$fs_spec" "$fs_file" || true
  fi
done <"$FSTAB_FILE"

if [ $error_count -gt 0 ]; then
  echo "Done: $error_count errors occurred." | { [ -n "${LOG_FILE:-}" ] && tee -a "$LOG_FILE" || cat; }
  exit 1
else
  echo "Done: all entries processed successfully." | { [ -n "${LOG_FILE:-}" ] && tee -a "$LOG_FILE" || cat; }
  exit 0
fi